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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 GLAST Large Area Telescope: Performance & Safety Assurance Joseph Cullinan SLAC Performance & Safety Assurance Manager cullinan@slac.stanford.edu (650) 926-5034 Gamma-ray Large Area Space Telescope
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Status August 2005 DAQ/Electronics TEM/TPS: -Have now completed handoff of 14 TEM/TPS assemblies to I&T -MRB held to review replacement of TPS units currently installed in Bays 0 and 4. -TPS units in the first two TEM/TPS assemblies installed in the Grid did not have CCA rework performed to eliminate voltage oscillation problem (NCR #397). -MRB concluded to remove TPS units only from Bays 0 and 4. Plan is to keep existing TEMs in Bays 0 and 4. Pros and cons of five different options hardware removal (including use-as-is) were considered -This option will allow for subsequent removal of TEM or TEM/CAL if replacement TPS fails to meet electrical or mechanical fit requirements -Replacement TPS units with HV calibration constants similar to those of the TPS units to be removed have been selected from fully tested TEM/TPS assemblies -TPS removal and replacement procedure being finalized and documented by I&T -Recalibration of new TEM/TPS telemetry and TKR and CAL detectors will be required following TPS replacement PDU: -T/V test started on 1 st box, 2 nd box delivered to SLAC for initial testing GASU: -GASU Power Supply boards and CCAs for 1 st GASU completed rework at SLAC following initial testing -Updating drawings and BOM to reflect changes -Boards and CCAs for 2 nd GASU still in assembly at Aeroflex
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Status August 2005 DAQ/Electronics LCB/SIB/CPS boards: -Last month LAT QA observed workmanship issues with first SIB, LCB and CPS boards delivered and reviewed these issues with Aeroflex and SLAC source inspector -Discrepancies were result of carelessness rather than unclear drawings or lack of technical expertise at Aeroflex -Corrective action: Aeroflex project management reviewed procedures with technicians to increase awareness of drawing requirements, hardware handling and workmanship requirements -SLAC source inspector now documents all in-process and final inspections and forwards reports to LAT QA and DAQ for review. -Discrepancies now are more clearly documented for evaluation. Any discrepancies that require rework is more quickly addressed by LAT/GSFC QA and DAQ, and if necessary additional corrective action can be implemented Cables: -Performing final inspection of remaining flight cables (including spares) at vendor facility (Cicon) this week.
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Status August 2005 Integration and Test -Supported completion of 6-tower and 8-tower testing -Supported receipt and acceptance of ACD -ACD final acceptance data package forthcoming -Elevated 4 open ACD nonconformances to LAT level NCRs
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Status August 2005 TKR -Supported MRB presented by INFN on Tower 8 tray anomaly observed during T/V testing (INFN NCR #551) -Ladders in Tray M007 began to show excessive noise or dead channels when temperatures rose above 25 deg. C -Similar failure was observed on Tray M010 on Tower 7. This tray was eventually removed and replaced, and Tower 7 retested -Both trays were fabricated for Tower 0 and subsequently requalified and placed into Towers 7 and 8 -MRB concurred to remove and replace tray M007 from Tower 8, and followed by repeat of environmental testing -Cause is unknown after considerable electrical testing on tray M010 -Testing on tray M010 to troubleshoot this problem appears to be exhausted; currently INFN does not have additional testing planned for tray M007 -INFN’s analysis indicates failure is typical of missing bias on Si detector and not wire bond intermittent failure -Additional Tower 0 requalified trays L023 and B002 are installed in flight Towers 4 and 5; no anomalies have been observed with these trays -INFN reported that insignificant performance degradation would result in Towers 4 and 5 ifthese trays began to show similar problems with ladders -Last flight tray (L015) from Tower 0 is now on hold at INFN
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Status August 2005 TKR Pioneer Flex Cables: -Supported in-process and final source inspection of cable assemblies at Pioneer -Pioneer has delivered qty = 29 finished cable assemblies; qty = 22 have been hand carried to INFN -Minor workmanship issues have been observed during source inspections -Omnetics connectors with damaged and bent pins from handling and worn test connector savers were removed and replaced without problems -Missing conformal coating observed on some resistors -On-site inspection and Pioneer’s responsiveness has allowed quick resolution of these workmanship issues. Causes were identified and corrective actions were put in place -GSFC has not rejected any Pioneer test coupons to date Parlex Flex Cables Qualification Test Plan: -Reviewed relevant documentation on Qual plan with GSFC and TKR -Will use flight and non-flight cables and coupons to complete qual testing -Non-flight cables will be hand selected to ensure qual testing will not be impacted by nonconforming condition of cable. Non-flight cables with slight annular ring failures would be best candidates. -Minor changes to the Parlex qualification test plan would include using cables instead of coupons for some tests.
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Status August 2005 Mechanical Systems X-LAT Plate -Delivered to SLAC in July; still awaiting acceptance data package from Lockheed Martin. -Lifting sling returned to LM for scheduled rework Radiators -T/V testing initiated
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 SubsystemOpen NCR’sClosed NCR Last 20 days # Over 30 Days Open DAQ57945 Tracker (SLAC)56553 Mechanical202 Calorimeter (SLAC)000 ACD (GSFC PRs and PFRs that are now LAT NCRs) 400 I&T281318 LAT NCR Metrics 8/26/05
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Status August 2005 Software QA -Supporting reviews of FSW test procedures -Supported the I&T release of LATTE R4.10.0 including V&V and documention review for LAT Docs. -Met with GSFC Software QA (Randy Worden) to discuss LAT QA processes for FSW oversight -QA requirements for FSW were reviewed -Randy provided recommendations for the LAT QA process overseeing FSW documentation and approval -SLAC reviewing these recommendations for implementation
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 Issues and Concerns Pioneer Flex Cables -Must ensure that coupon testing at GSFC keeps up with cable production and delivery to INFN, so we don’t end up waiting for a test report before a cable can be installed on a tower. -GSFC has provided exceptional support in prioritizing coupon testing in response to a highly accelerated delivery schedule for Pioneer cables, so the process is working so far. Tower testing -TKR, INFN and LAT QA need to closely follow the process for removing non-flight cables used to support tower environmental testing, and the subsequent replacement of flight cables Towers 7, 8 tray anomalies observed in T/V -Cause is still unknown, and currently there are no known additional tests or analyses on removed trays to determine cause
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 4.1.A P&SA – Planned Accomplishments September 2005 Support PDU, GASU testing Support electronics assembly at Aeroflex Support flex cable production at Pioneer Support flex cable qual testing at Parlex
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 Cost Report
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 Cost Variance Explanation Why overrun/underrun? -Did not reduce headcount to follow planned FTE dropoff due to extended production runs through end of July at Teledyne and General Technology with full time source quality engineers. Also required same headcount as last month to support subsystem production and testing. What will be done to correct? -Source quality engineers at Teledyne and General Technology have rolled off as of end of July (2 FTE) -Look to consolidate QA headcount at SLAC in September as subsystem production (cables, flex cables, incoming inspection) ramps down
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 FTE Report (DOE/NASA-funded only)
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GLAST LAT ProjectMonthly Status Review – Sept. 1, 2005 FTE Variance Explanation Why overrun/underrun? -Source QA support was needed longer than expected at Teledyne and General Technology to support production. Also needed to continue current level of QE support at SLAC What is the impact? -2 FTE required to support extended production cycles at these two vendors What will be done to correct? -Roll off of 2 source QEs at end of July is reduction of 2 FTE for August. Will also see additional reduction of approximately 1 FTE in August due to vacations. Also look to consolidate FTE at SLAC in September as vendor production runs near completion.
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